China Inst Atom Energy, Beijing 102413, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
This paper describes a new system for monitoring leaks in a steam generator. The new system extends the traditional N-16 monitor to detect both the rate and the location of a leak. Because the transit time is different for radioactive N-16 and O-19 to travel from the reactor core via the hot bottom side, cold bottom side, or bend region of the U-tube in a steam generator to the gamma-ray detector, the new system uses the different transit times to identify the location of leaks. Specifically, the ratio So of N-16 to O-19 activities in the reactor core of a swimming pool reactor was calculated by combining the cross sections sigma(np)(E) and sigma(ny)(E) with the neutron spectra phi(n)(E). The ratio S-1 of N-16 to O-19 activities in the measurement room was also calculated and measured by the high-purity germanium and NaI(Tl) detectors. The result of the calculation agrees with the measurement within an acceptable range.